Im my react native project's native module I need to send some data periodically from Objective-C to Swift so I am using NSNotificationCenter. I receive the data successfully in my Swift class, inside the function attached to the observer, and I store it in a property.
If I access this property from any instance method call I can see that the value has updated.
However if I access the same property in the selector function attached to the Timer it appears as if the value has not been updated and I cannot figure out why? It seems as if the timer selector function does not have access to anything except the initial value of the property - I have also tried passing the property as part of userInfo to the Timer but the issue is the same.
[[NSNotificationCenter defaultCenter] postNotificationName:@"stateDidUpdate" object:nil userInfo:state];class StateController { var state: Dictionary<String, Any> = Dictionary() var timer: Timer = Timer() func subscribeToNotifications() { NotificationCenter.default.addObserver( self, selector: #selector(receivedStateUpdate), name: NSNotification.Name.init(rawValue: "stateDidUpdate"), object: nil) } @objc func receivedStateUpdate(notification: NSNotification) { if let state = notification.userInfo { self.state = (state as? Dictionary<String, Any>)! print("\(self.state)") // I can see that self.state has been updated here } } func runTimer() { self.timer = Timer(timeInterval: 0.1, target: self, selector: #selector(accessState(timer:)), userInfo: nil, repeats: true) self.timer.fire() RunLoop.current.add(self.timer, forMode: RunLoop.Mode.default) RunLoop.current.run(until: Date(timeIntervalSinceNow: 2)) } @objc func accessState(timer: Timer) { print("\(self.state)") // state is an empty Dictionary when accessed here } func printState() {"\(self.state)" // value printed is the updated value received from the notification }}